Desk lamp



FIG. 1 is a front, top and right side perspective view of a desk lamp showing our new design;

FIG. 2 is a bottom, rear and left side perspective view;

FIG. 3 is a right side view;

FIG. 4 is a top plan view; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a desk lamp, as shown. 